US12219540B2 - Systems and methods to include demodulation reference signal bundling in multi-subscriber identity module devices - Google Patents

Abstract

A method of wireless communication performed by a user equipment (UE) includes: operating in a dual SIM dual active (DSDA) mode with respect to a first subscriber identity module (SIM) and a second SIM; controlling transmit operations of the first SIM and the second SIM according to a time division multiplexed (TDM) priority pattern; performing demodulation reference signal (DMRS) bundling on the first SIM, the first SIM having a higher priority state according to the TDM priority pattern; and deferring a priority switch to give the higher priority state to the second SIM until after the first SIM has completed a repetition of DMRS bundling.

Description

TECHNICAL FIELD

This application relates to wireless communication systems, and more particularly improving throughput when using demodulation reference signal (DMRS) bundling in multi-subscriber identity module (multi-SIM) devices.

INTRODUCTION

Wireless communications systems are widely deployed to provide various types of communication content such as voice, video, packet data, messaging, broadcast, and so on. These systems may be capable of supporting communication with multiple users by sharing the available system resources (e.g., time, frequency, and power). A wireless multiple-access communications system may include a number of base stations (BSs), each simultaneously supporting communications for multiple communication devices, which may be otherwise known as user equipment (UE).

To meet the growing demands for expanded mobile broadband connectivity, wireless communication technologies are advancing from the long term evolution (LTE) technology to a next generation new radio (NR) technology, which may be referred to as 5^thGeneration (5G). For example, NR is designed to provide a lower latency, a higher bandwidth or a higher throughput, and a higher reliability than LTE. NR is designed to operate over a wide array of spectrum bands, for example, from low-frequency bands below about 1 gigahertz (GHz) and mid-frequency bands from about 1 GHz to about 6 GHz, to high-frequency bands such as millimeter wave (mmWave) bands. NR is also designed to operate across different spectrum types, from licensed spectrum to unlicensed and shared spectrum. Furthermore, as wireless communication becomes cheaper and more reliable, expectations among consumers change. Some UE manufacturers are responding to consumer preferences by including multiple subscriber identity modules (SIMs) within UEs.

However, including multiple SIMs within a device may lead to scenarios in which activities by one SIM may interfere with or preclude activities by the other SIM. There is a need in the art for techniques to manage use of multiple subscriptions in multi-SIM devices, including in those that use demodulation reference signal (DMRS) bundling.

BRIEF SUMMARY OF SOME EXAMPLES

The following summarizes some aspects of the present disclosure to provide a basic understanding of the discussed technology. This summary is not an extensive overview of all contemplated features of the disclosure and is intended neither to identify key or critical elements of all aspects of the disclosure nor to delineate the scope of any or all aspects of the disclosure. Its sole purpose is to present some concepts of one or more aspects of the disclosure in summary form as a prelude to the more detailed description that is presented later.

In one aspect of the disclosure, a method of wireless communication performed by a user equipment (UE) includes: operating in a dual SIM dual active (DSDA) mode with respect to a first subscriber identity module (SIM) and a second SIM; controlling transmit operations of the first SIM and the second SIM according to a time division multiplexed (TDM) priority pattern; performing demodulation reference signal (DMRS) bundling on the first SIM, the first SIM having a higher priority state according to the TDM priority pattern; and deferring a priority switch to give the higher priority state to the second SIM until after the first SIM has completed a repetition of DMRS bundling.

In an additional aspect of the disclosure, a user equipment (UE) includes: a first subscriber identity module (SIM) associated with a first service provider subscription and a second SIM associated with a second service provider subscription; and a processor configured to access the first SIM and the second SIM, where the processor is further configured to: receiving information indicating a first band for use with the first SIM and a second band for use with the second SIM; determining that the first band and the second band are incompatible with demodulation reference signal (DMRS) bundling in a dual SIM dual active (DSDA) operating mode; and informing a base station that DMRS bundling is unavailable at the UE.

In an additional aspect of the disclosure, a non-transitory computer-readable medium having program code recorded thereon for wireless communication by a UE, the program code includes: code for operating in a dual SIM dual active (DSDA) mode with respect to a first subscriber identity module (SIM) and a second SIM; code for controlling transmit operations of the first SIM and the second SIM according to a time division multiplexed (TDM) priority pattern; code for performing demodulation reference signal (DMRS) bundling on the first SIM, the first SIM having a higher priority state according to the TDM priority pattern; and code for switching the higher priority state to the second SIM during the DMRS bundling on the first SIM; and code for reducing a transmit power of the first SIM during the DMRS bundling on the first SIM, including maintaining phase continuity of the first SIM.

In an additional aspect of the disclosure, a UE includes means for receiving information indicating a first band for use with a first subscriber identity module (SIM) and a second band for use with a second SIM; means for determining that the first band and the second band are incompatible with demodulation reference signal (DMRS) bundling in a dual SIM dual active (DSDA) operating mode; and means for taking an action with respect to DMRS bundling in response to determining that the first band and the second band are incompatible with DMRS bundling, including either one or both of: means for advertising a lack of capability for DMRS bundling and means for requesting that DMRS bundling be disabled.

Other aspects, features, and embodiments will become apparent to those of ordinary skill in the art, upon reviewing the following description of specific, exemplary aspects in conjunction with the accompanying figures. While features may be discussed relative to certain aspects and figures below, all aspects can include one or more of the advantageous features discussed herein. In other words, while one or more aspects may be discussed as having certain advantageous features, one or more of such features may also be used in accordance with the various aspects discussed herein. In similar fashion, while exemplary aspects may be discussed below as device, system, or method aspects it should be understood that such exemplary aspects can be implemented in various devices, systems, and methods.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG.1 illustrates an example wireless communication network according to some aspects of the present disclosure.

FIG.2 illustrates an example communication scenario utilizing multiple subscriptions according to some aspects of the present disclosure.

FIG.3 is a block diagram of an example hardware architecture of a UE, such as the UEs ofFIGS.1-2, according to some aspects of the present disclosure.

FIGS.4-6 are example timelines for transmitting and receiving in a multi-SIM device, according to some aspects of the disclosure.

FIG.7 is a diagram of an example method for accommodating DMRS bundling in a multi-SIM device, according to some aspects of the present disclosure.

FIG.8 is a diagram of an example method for accommodating DMRS bundling in a multi-SIM device, according to some aspects of the present disclosure.

FIG.9 is a diagram of an example method for accommodating DMRS bundling in a multi-SIM device, according to some aspects of the present disclosure.

FIG.10 illustrates a block diagram of an example user equipment (UE) according to some aspects of the present disclosure.

FIG.11 illustrates a block diagram of an example base station (BS) according to some aspects of the present disclosure.

DETAILED DESCRIPTION

The detailed description set forth below, in connection with the appended drawings, is intended as a description of various configurations and is not intended to represent the only configurations in which the concepts described herein may be practiced. The detailed description includes specific details for the purpose of providing a thorough understanding of the various concepts. However, it will be apparent to those skilled in the art that these concepts may be practiced without these specific details. In some aspects, well-known structures and components are shown in block diagram form in order to avoid obscuring such concepts.

This disclosure relates generally to wireless communications systems, also referred to as wireless communications networks. In various aspects, the techniques and apparatus may be used for wireless communication networks such as code division multiple access (CDMA) networks, time division multiple access (TDMA) networks, frequency division multiple access (FDMA) networks, orthogonal FDMA (OFDMA) networks, single-carrier FDMA (SC-FDMA) networks, LTE networks, Global System for Mobile Communications (GSM) networks, 5^thGeneration (5G) or new radio (NR) networks, as well as other communications networks. As described herein, the terms “networks” and “systems” may be used interchangeably.

An OFDMA network may implement a radio technology such as evolved UTRA (E-UTRA), Institute of Electrical and Electronics Engineers (IEEE) 802.11, IEEE 802.16. IEEE 802.20, flash-OFDM and the like. UTRA. E-UTRA, and GSM are part of universal mobile telecommunication system (UMTS). In particular, long term evolution (LTE) is a release of UMTS that uses E-UTRA. UTRA, E-UTRA, GSM, UMTS and LTE are described in documents provided from an organization named “3rd Generation Partnership Project” (3GPP), and cdma2000 is described in documents from an organization named “3rd Generation Partnership Project 2” (3GPP2). These various radio technologies and standards are known or are being developed. For example, the 3rd Generation Partnership Project (3GPP) is a collaboration between groups of telecommunications associations that aims to define a globally applicable third generation (3G) mobile phone specification. 3GPP long term evolution (LTE) is a 3GPP project which was aimed at improving the UMTS mobile phone standard. The 3GPP may define specifications for the next generation of mobile networks, mobile systems, and mobile devices. The present disclosure is concerned with the evolution of wireless technologies from LTE, 4G, 50, NR, and beyond with shared access to wireless spectrum between networks using a collection of new and different radio access technologies or radio air interfaces.

In particular, 5G networks contemplate diverse deployments, diverse spectrum, and diverse services and devices that may be implemented using an OFDM-based unified, air interface. To achieve these goals, further enhancements to LTE and LTE-A are considered in addition to development of the new radio technology for 5G NR networks. The 5G NR will be capable of scaling to provide coverage (1) to a massive Internet of things (IoTs) with a ULtra-high density (e.g., ˜1 M nodes/km²), ultra-low complexity (e.g., ˜10 s of bits/sec), ultra-low energy (e.g., ˜10+ years of battery life), and deep coverage with the capability to reach challenging locations; (2) including control with strong security to safeguard sensitive personal, financial, or classified information, ultra-high reliability (e.g., ˜99.9999% reliability), ultra-low latency (e.g., ˜1 ms), and users with wide ranges of mobility or lack thereof; and (3) with enhanced mobile broadband including extreme high capacity (e.g., ˜10 Tbps/km²), extreme data rates (e.g., multi-Gbps rate, 100+ Mbps user experienced rates), and deep awareness with advanced discovery and optimizations.

A 5G NR system may be implemented to use optimized OFDM-based waveforms with scalable numerology and transmission time interval (TTI); having a common, flexible framework to efficiently multiplex services and features with a dynamic, low-latency time division duplex (TDD)/frequency division duplex (FDD) design; and with advanced wireless technologies, such as massive multiple input, multiple output (MIMO), robust millimeter wave (mmWave) transmissions, advanced channel coding, and device-centric mobility. Scalability of the numerology in 5G NR, with scaling of subcarrier spacing, may efficiently address operating diverse services across diverse spectrum and diverse deployments. For example, in various outdoor and macro coverage deployments of less than 3 GHz FDD/TDD implementations, subcarrier spacing may occur with 15 kHz, for example over 5, 10, 20 MHz, and the like bandwidth (BW). For other various outdoor and small cell coverage deployments of TDD greater than 3 GHz, subcarrier spacing may occur with 30 kHz over 80/100 MHz BW. For other various indoor wideband implementations, using a TDD over the unlicensed portion of the 5 GHz band, the subcarrier spacing may occur with 60 kHz over a 160 MHz BW. Finally, for various deployments transmitting with mmWave components at a TDD of 28 GHz, subcarrier spacing may occur with 120 kHz over a 500 MHz BW. In certain aspects, frequency bands for 5G NR are separated into two different frequency ranges, a frequency range one (FR1) and a frequency range two (FR2). FR1 bands include frequency bands at 7 GHz or lower (e.g., between about 410 MHz to about 7125 MHz). FR2 bands include frequency bands in mmWave ranges between about 24.25 GHz and about 52.6 GHz. The mmWave bands may have a shorter range, but a higher bandwidth than the FR1 bands. Additionally, 5G NR may support different sets of subcarrier spacing for different frequency ranges.

The scalable numerology of the 5G NR facilitates scalable TTI for diverse latency and quality of service (QoS) requirements. For example, shorter TTI may be used for low latency and high reliability, while longer TTI may be used for higher spectral efficiency. The efficient multiplexing of long and short TTIs to allow transmissions to start on symbol boundaries. 5G NR also contemplates a self-contained integrated subframe design with UI/downlink scheduling information, data, and acknowledgement in the same subframe. The self-contained integrated subframe supports communications in unlicensed or contention-based shared spectrum, adaptive UL/downlink that may be flexibly configured on a per-cell basis to dynamically switch between UL and downlink to meet the current traffic needs.

Various other aspects and features of the disclosure are further described below. It should be apparent that the teachings herein may be embodied in a wide variety of forms and that any specific structure, function, or both being disclosed herein is merely representative and not limiting. Based on the teachings herein one of an ordinary level of skill in the art should appreciate that an aspect disclosed herein may be implemented independently of any other aspects and that two or more of these aspects may be combined in various ways. For example, an apparatus may be implemented or a method may be practiced using any number of the aspects set forth herein. In addition, such an apparatus may be implemented or such a method may be practiced using other structure, functionality, or structure and functionality in addition to or other than one or more of the aspects set forth herein. For example, a method may be implemented as part of a system, device, apparatus, and/or as instructions stored on a computer readable medium for execution on a processor or computer. Furthermore, an aspect may comprise at least one element of a claim.

In certain aspects, a wireless communication device or UE is a multiple SIM (multi-SIM) device capable of utilizing multiple subscriptions for communication with one or more networks. For instance, the UE may include two SIMs, a first SIM for a first subscription and a second SIM for a second subscription. In some instances, the first and second subscriptions may be provided by the same operator. For example, the first subscription and the second subscription may correspond to different user accounts and/or services on the same operator network. In other instances, the first and second subscriptions may be provided by different operators. In any case, in certain scenarios, the UE may communicate using the first subscription and/or the second subscription. In some instances, the UE may operate in a dual-SIM dual-standby (DSDS) mode, where both subscriptions can be on standby (in an idle mode) waiting to begin communications. However, when a communication or network connection is established on one SIM (e.g., the first subscription), the other SIM (e.g., the second subscription) is no longer active. That is, one SIM may be active at a given time. The DSDS mode may be suitable for UEs that are equipped with a single transceiver and/or radio frequency (RF) chain which can either be utilized by the first subscription or the second subscription. In other instances, the UE may operate in a dual-SIM dual-active (DSDA) mode, where the UE may simultaneously connect to the same network or different networks via the first SIM and the second SIM. To operate in the DSDA mode, the UE may have separate transceiver and/or RF chains or resources for the first SIM and the second SIM. In the present disclosure, an operation or communication performed via a SIM may refer to an operation or communication performed for a wireless service subscription associated with the SIM (where the subscription information for the wireless service is stored).

The concept of demodulation reference signal (DMRS) bundling has been introduced for use across both physical UL shared channel (PUSCH) repetitions and PUSCHs with different transport blocks (TBs). DMRS bundling may be an effective technique for enhancing cell coverage, including for uplink (UL) communications near the edge or boundary of a cell. At the UE, the DMRSs can be coherently transmitted over different time instants corresponding to different uplink transmissions (e.g., PUSCH transmissions and/or physical UL control channel (PUCCH) transmissions). At the BS, the DMRSs received over different time instants can be coherently filtered and/or combined to enhance the accuracy of channel estimation. That is, the DMRSs received over the different time instants can be processed jointly instead of separately or individually.

However, a constraint of DMRS bundling is that the UE may be required to maintain phase coherence and continuity across the different DMRSs in different PUSCH slots within the bundle. There may be scenarios that impact the UEs phase continuity ability, such as transmit power changes, timing advance application, retune requirement do to uplink switching, and the like. In other words, while DMRS bundling may be beneficial in some instances, it may pose problems in other instances.

Currently, 3rd Generation Partnership Project (3GPP) is working to implement rules for use of DMRS bundling. For instance, one proposed rule would not require UEs to perform timing advance application, transmit power changes due to transmit power control, and the like which might impact phase continuity while in a current DMRS repetition window. Another proposed rule would expect the network to not change or request a configuration during a current repetition window if that configuration change would impact UE phase continuity.

Such rules might be helpful for single-SIM UEs, but there are specific issues relating to multi-SIM UEs to be addressed. In one example, there are phase continuity requirements in transmit chain sharing in DSDA in which a transmitter chain is shared or retuned across the two SIMs. In another example, there are coexistence scenarios where the transmit power chain is backed off based on a configuration of the other SIM.

In one example, a UE receives information indicating a first band for use with the first SIM and a second band for use with the second SIM. For instance, the UE may receive the information from the network itself or from an application (e.g., a machine learning application) that predicts which bands will be configured for the SIMs. The UE may then determine that the first band and the second band are incompatible with DMRS bundling for a DSDA operating mode. For instance, the two different bands may not be supported for full concurrency and may instead be operated only in a transmit sharing mode. In another example, the band used by the first SIM may be associated with a transmit power back off during reception by the second SIM, where transmit power back off may interfere with phase coherence during DMRS bundling.

Continuing with the example, the UE may then inform the base station that interacts with the first SIM that DMRS bundling is unavailable at the UE. For instance, the UE may provide a capability report to the base station to indicate an inability to support DMRS bundling. In another example, the UE may indicate to the base station that DMRS bundling is unavailable by requesting that the base station disable DMRS bundling at least temporarily.

In another example, the UE operates in a DSDA mode and controls transmit operations of the first SIM and the second SIM according to a time division multiplexed (TDM) priority pattern. The first SIM may perform DMRS bundling, the first SIM having a higher priority state according to the TDM priority pattern. This may include deferring a priority switch to give the higher priority state to the second SIM until after the first SIM has completed a repetition of DMRS bundling. If extra time is added to the first SIM's priority status, then after the priority switch, similar added time may be given to the second SIM.

In yet another example, the UE may apply a transmit back off for the first SIM in the middle of the DMRS bundle by using filter output scaling in the baseband to help maintain phase continuity. Similarly, the UE may lower a power amplifier state to adjust to reduce the transmit power, and the transmit front end may then compensate for the power amplifier adjustment. Still, such approach may allow for phase coherence to be maintained.

Various implementations may include advantages. For instance, implementations that disable or otherwise advertise an inability to use DMRS bundling may avoid performance penalties that would be imposed by the network if the UE were to attempt DMRS bundling but failed to maintain phase coherence. In other words, throughput gained by not using DMRS bundling in some scenarios may outweigh any benefit that would have otherwise been provided by DMRS bundling.

In another example, implementations that adjust a priority assigned by a TDM priority pattern may benefit from both SIMs being able to transmit full DMRS bundles while maintaining fairness between the SIMs. In another implementation that performs DMRS bundling but compensates by using filter output scaling in baseband or by using a transmit front end, that implementation may also allow both SIMs to transmit full DMRS bundles while maintaining fairness between the SIMs. Once again, DMRS bundling may allow for an increase in overall UL performance by providing the base station with a reference signal that it can use for channel estimation and UL grants. Increasing a use of DMRS bundling, or at least avoiding attempting DMRS bundling when it may fail, may thus result in a higher UL throughput despite any technical issues arising from multi-SIM UEs.

FIG.1 illustrates awireless communication network100 according to some aspects of the present disclosure. Thenetwork100 may be a 5G network. Thenetwork100 includes a number of base stations (BSs)105 (individually labeled as105a,105b,105c,105d,105e, and105f) and other network entities. A BS105 may be a station that communicates with UEs115 (individually labeled as115a,115b,1115c,115d,115e,115f,115g,115h, and115k) and may also be referred to as an evolved node B (eNB), a next generation eNB (gNB), an access point, and the like. Each BS105 may provide communication coverage for a particular geographic area. In 3GPP, the term “cell” can refer to this particular geographic coverage area of a BS105 and/or a BS subsystem serving the coverage area, depending on the context in which the term is used.

A BS105 may provide communication coverage for a macro cell or a small cell, such as a pico cell or a femto cell, and/or other types of cell. A macro cell generally covers a relatively large geographic area (e.g., several kilometers in radius) and may allow unrestricted access by UEs with service subscriptions with the network provider. A small cell, such as a pico cell, would generally cover a relatively smaller geographic area and may allow unrestricted access by UEs with service subscriptions with the network provider. A small cell, such as a femto cell, would also generally cover a relatively small geographic area (e.g., a home) and, in addition to unrestricted access, may also provide restricted access by UEs having an association with the femto cell (e.g., UEs in a closed subscriber group (CSG), UEs for users in the home, and the like). A BS for a macro cell may be referred to as a macro BS. A BS for a small cell may be referred to as a small cell BS, a pico BS, a femto BS or a home BS. In the example shown inFIG.1, theBSs105dand105emay be regular macro BSs, while the BSs105a-105cmay be macro BSs enabled with one of three dimension (3D), full dimension (FD), or massive MIMO. The BSs105a-105cmay take advantage of their higher dimension MIMO capabilities to exploit 3D beamforming in both elevation and azimuth beamforming to increase coverage and capacity. TheBS105fmay be a small cell BS which may be a home node or portable access point. A BS105 may support one or multiple (e.g., two, three, four, and the like) cells.

Thenetwork100 may support synchronous or asynchronous operation. For synchronous operation, the BSs may have similar frame timing, and transmissions from different BSs may be approximately aligned in time. For asynchronous operation, the BSs may have different frame timing, and transmissions from different BSs may not be aligned in time.

TheUEs115 are dispersed throughout thewireless network100, and eachUE115 may be stationary or mobile. AUE115 may also be referred to as a terminal, a mobile station, a subscriber unit, a station, or the like. AUE115 may be a cellular phone, a personal digital assistant (PDA), a wireless modem, a wireless communication device, a handheld device, a tablet computer, a laptop computer, a cordless phone, a wireless local loop (WLL) station, or the like. In one aspect, aUE115 may be a device that includes a Universal Integrated Circuit Card (UICC). In another aspect, a UE may be a device that does not include a UICC. In some aspects, theUEs115 that do not include UICCs may also be referred to as IoT devices or internet of everything (IoE) devices. TheUEs115a-115dare examples of mobile smart phone-typedevices accessing network100. AUE115 may also be a machine specifically configured for connected communication, including machine type communication (MTC), enhanced MTC (eMTC), narrowband IoT (NB-IoT) and the like. TheUEs115e-115hare examples of various machines configured for communication that access thenetwork100. TheUEs115i-115kare examples of vehicles equipped with wireless communication devices configured for communication that access thenetwork100. AUE115 may be able to communicate with any type of the BSs, whether macro BS, small cell, or the like. InFIG.1, a lightning bolt (e.g., communication links) indicates wireless transmissions between aUE115 and a serving BS105, which is a BS designated to serve theUE115 on the downlink (DL) and/or uplink (UL), desired transmission between BSs105, backhaul transmissions between BSs, or sidelink transmissions betweenUEs115.

In operation, the BSs105a-105cmay serve theUEs115aand115busing 3D beamforming and coordinated spatial techniques, such as coordinated multipoint (CoMP) or multi-connectivity. Themacro BS105dmay perform backhaul communications with the BSs105a-105c, as well as small cell, theBS105f. Themacro BS105dmay also transmits multicast services which are subscribed to and received by theUEs115cand115d. Such multicast services may include mobile television or stream video, or may include other services for providing community information, such as weather emergencies or alerts, such as Amber alerts or gray alerts.

The BSs105 may also communicate with a core network. The core network may provide user authentication, access authorization, tracking, Internet Protocol (IP) connectivity, and other access, routing, or mobility functions. At least some of the BSs105 (e.g., which may be an example of a gNB or an access node controller (ANC)) may interface with the core network through backhaul links (e.g., NG-C, NG-U, etc.) and may perform radio configuration and scheduling for communication with theUEs115. In various examples, the BSs105 may communicate, either directly or indirectly (e.g., through core network), with each other over backhaul links (e.g., X1, X2, etc.), which may be wired or wireless communication links.

Thenetwork100 may also support communications with ultra-reliable and redundant links for devices, such as theUE115e, which may be airborne. Redundant communication links with theUE115emay include links from themacro BSs105dand105e, as well as links from thesmall cell BS105f. Other machine type devices, such as theUE115f(e.g., a thermometer), theUE115g(e.g., smart meter), andUE115h(e.g., wearable device) may communicate through thenetwork100 either directly with BSs, such as thesmall cell BS105f, and themacro BS105e, or in multi-action-size configurations by communicating with another user device which relays its information to the network, such as theUE115fcommunicating temperature measurement information to the smart meter, theUE115g, which is then reported to the network through thesmall cell BS105f. Thenetwork100 may also provide additional network efficiency through dynamic, low-latency TDD/FDD communications, such as V2V, V2X, C-V2X communications between aUE115i.115j, or115kandother UEs115, and/or vehicle-to-infrastructure (V2I) communications between aUE115i,115j, or115kand a BS105.

In some implementations, thenetwork100 utilizes OFDM-based waveforms for communications. An OFDM-based system may partition the system BW into multiple (K) orthogonal subcarriers, which are also commonly referred to as subcarriers, tones, bins, or the like. Each subcarrier may be modulated with data. In some aspects, the subcarrier spacing between adjacent subcarriers may be fixed, and the total number of subcarriers (K) may be dependent on the system BW. The system BW may also be partitioned into subbands. In other aspects, the subcarrier spacing and/or the duration of TTIs may be scalable.

In some aspects, the BSs105 can assign or schedule transmission resources (e.g., in the form of time-frequency resource blocks (RB)) for downlink (DL) and uplink (UL) transmissions in thenetwork100. DL refers to the transmission direction from a BS105 to aUE115, whereas UL refers to the transmission direction from aUE115 to a BS105. The communication can be in the form of radio frames. A radio frame may be divided into a plurality of subframes or slots, for example, about 10. Each slot may be further divided into mini-slots. In a FDD mode, simultaneous UL and DL transmissions may occur in different frequency bands. For example, each subframe includes a UL subframe in a UL frequency band and a DL subframe in a DL frequency band. In a TDD mode, UL and DL transmissions occur at different time periods using the same frequency band. For example, a subset of the subframes (e.g., DL subframes) in a radio frame may be used for DL transmissions and another subset of the subframes (e.g., UL subframes) in the radio frame may be used for UL transmissions.

The DL subframes and the UL subframes can be further divided into several regions. For example, each DL or UL subframe may have pre-defined regions for transmissions of reference signals, control information, and data. Reference signals are predetermined signals that facilitate the communications between the BSs105 and theUEs115. For example, a reference signal can have a particular pilot pattern or structure, where pilot tones may span across an operational BW or frequency band, each positioned at a pre-defined time and a pre-defined frequency. For example, a BS105 may transmit cell specific reference signals (CRSs) and/or channel state information—reference signals (CSI-RSs) to enable aUE115 to estimate a DL channel. Similarly, aUE115 may transmit sounding reference signals (SRSs) to enable a BS105 to estimate a UL channel. Control information may include resource assignments and protocol controls. Data may include protocol data and/or operational data. In some aspects, the BSs105 and theUEs115 may communicate using self-contained subframes. A self-contained subframe may include a portion for DL communication and a portion for UL communication. A self-contained subframe can be DL-centric or UL-centric. A DL-centric subframe may include a longer duration for DL communication than for UL communication. A UL-centric subframe may include a longer duration for UL communication than for UL communication.

In some aspects, thenetwork100 may be an NR network deployed over a licensed spectrum. The BSs105 can transmit synchronization signals (e.g., including a primary synchronization signal (PSS) and a secondary synchronization signal (SSS)) in thenetwork100 to facilitate synchronization. The BSs105 can broadcast system information associated with the network100 (e.g., including a master information block (MIB), remaining system information (RMSI), and other system information (OSI)) to facilitate initial network access. In some aspects, the BSs105 may broadcast the PSS, the SSS, and/or the MIB in the form of synchronization signal block (SSBs) and may broadcast the RMSI and/or the OSI over a physical downlink shared channel (PDSCH). The MIB may be transmitted over a physical broadcast channel (PBCH).

In some aspects, aUE115 attempting to access thenetwork100 may perform an initial cell search by detecting a PSS from a BS105. The PSS may enable synchronization of period timing and may indicate a physical layer identity value. TheUE115 may then receive a SSS. The SSS may enable radio frame synchronization, and may provide a cell identity value, which may be combined with the physical layer identity value to identify the cell. The PSS and the SSS may be located in a central portion of a carrier or any suitable frequencies within the carrier.

After receiving the PSS and SSS, theUE115 may receive a MIB. The MIB may include system information for initial network access and scheduling information for RMSI and/or OSI. After decoding the MIB, theUE115 may receive RMSI and/or OSI. The RMSI and/or OSI may include radio resource control (RRC) information related to random access channel (RACH) procedures, paging, control resource set (CORESET) for physical downlink control channel (PDCCH) monitoring, physical UL control channel (PUCCH), physical UL shared channel (PUSCH), power control, and SRS.

After obtaining the MIB, the RMSI and/or the OSI, theUE115 can perform a random access procedure to establish a connection with the BS105. In some examples, the random access procedure may be a four-step random access procedure. For example, theUE115 may transmit a random access preamble and the BS105 may respond with a random access response. The random access response (RAR) may include a detected random access preamble identifier (ID) corresponding to the random access preamble, timing advance (TA) information, a UL grant, a temporary cell-radio network temporary identifier (C-RNTI), and/or a backoff indicator. Upon receiving the random access response, theUE115 may transmit a connection request to the BS105 and the BS105 may respond with a connection response. The connection response may indicate a contention resolution. In some examples, the random access preamble, the RAR, the connection request, and the connection response can be referred to as message 1 (MSG1), message 2 (MSG2), message 3 (MSG3), and message 4 (MSG4), respectively. In some examples, the random access procedure may be a two-step random access procedure, where theUE115 may transmit a random access preamble and a connection request in a single transmission and the BS105 may respond by transmitting a random access response and a connection response in a single transmission.

After establishing a connection, theUE115 and the BS105 can enter a normal operation stage, where operational data may be exchanged. For example, the BS105 may schedule theUE115 for UL and/or DL communications. The BS105 may transmit UL and/or DL scheduling grants to theUE115 via a PDCCH. The scheduling grants may be transmitted in the form of DL control information (DCI). The BS105 may transmit a DL communication signal (e.g., carrying data) to theUE115 via a PDSCH according to a DL scheduling grant. TheUE115 may transmit a UL communication signal to the BS105 via a PUSCH and/or PUCCH according to a UL scheduling grant. The connection may be referred to as an RRC connection. When theUE115 is actively exchanging data with the BS105, theUE115 is in an RRC connected state.

In an example, after establishing a connection with the BS105, theUE115 may initiate an initial network attachment procedure with thenetwork100. The BS105 may coordinate with various network entities or fifth generation core (5GC) entities, such as an access and mobility function (AMF), a serving gateway (SGW), and/or a packet data network gateway (PGW), to complete the network attachment procedure. For example, the BS105 may coordinate with the network entities in the 5GC to identify the UE, authenticate the UE, and/or authorize the UE for sending and/or receiving data in thenetwork100. In addition, the AMF may assign the UE with a group of tracking areas (TAs). Once the network attach procedure succeeds, a context is established for theUE115 in the AMF. After a successful attach to the network, theUE115 can move around the current TA. For tracking area update (TAU), the BS105 may request theUE115 to update thenetwork100 with theUE115's location periodically. Alternatively, theUE115 may only report theUE115's location to thenetwork100 when entering a new TA. The TAU allows thenetwork100 to quickly locate theUE115 and page theUE115 upon receiving an incoming data packet or call for theUE115.

In some aspects, the BS105 may communicate with aUE115 using HARQ techniques to improve communication reliability, for example, to provide a URLLC service. The BS105 may schedule aUE115 for a PDSCH communication by transmitting a DL grant in a PDCCH. The BS105 may transmit a DL data packet to theUE115 according to the schedule in the PDSCH. The DL data packet may be transmitted in the form of a transport block (TB). If theUE115 receives the DL data packet successfully, theUE115 may transmit a HARQ ACK to the BS105. Conversely, if theUE115 fails to receive the DL transmission successfully, theUE115 may transmit a HARQ NACK to the BS105. Upon receiving a HARQ NACK from theUE115, the BS105 may retransmit the DL data packet to theUE115. The retransmission may include the same coded version of DL data as the initial transmission. Alternatively, the retransmission may include a different coded version of the DL data than the initial transmission. TheUE115 may apply soft combining to combine the encoded data received from the initial transmission and the retransmission for decoding. The BS105 and theUE115 may also apply HARQ for UL communications using substantially similar mechanisms as the DL HARQ.

In some aspects, thenetwork100 may operate over a system BW or a component carrier (CC) BW. Thenetwork100 may partition the system BW into multiple BWPs (e.g., portions). A BS105 may dynamically assign aUE115 to operate over a certain BWP (e.g., a certain portion of the system BW). The assigned BWP may be referred to as the active BWP. TheUE115 may monitor the active BWP for signaling information from the BS105. The BS105 may schedule theUE115 for UL or DL communications in the active BWP. In some aspects, a BS105 may assign a pair of BWPs within the CC to aUE115 for UL and DL communications. For example, the BWP pair may include one BWP for UL communications and one BWP for DL communications.

In some aspects, aUE115 may be capable of utilizing multiple SIMs and may accommodate DMRS bundling, as explained in more detail below.

FIG.2 illustrates acommunication scenario200 that utilizes multiple subscriptions according to some aspects of the present disclosure. Thecommunication scenario200 may correspond to a communication scenario among BSs105 and orUEs115 in thenetwork100. For simplicity,FIG.2 illustrates two BSs205 (shown as205aand205b) and oneUE215, but a greater number of UEs215 (e.g., the about 3, 4, 3, 6, 7, 8, 9, 10, or more) and/or BSs205 (e.g., the about 3, 4 or more) may be supported. The BS205 and theUEs215 may be similar to the BSs105 and theUEs115, respectively.

In thescenario200, theUE215 is capable of utilizing multiple SIMs (e.g., SIM cards) for communication with one or more networks. For simplicity,FIG.2 illustrates theUE215 including two SIMs210 (shown asSIM A210aandSIM B210b), but theUE215 may include more than two SIMs (e.g., about 3, 4 or more). In some aspects, each SIM210 may include integrated circuits and/or memory configured to store information used for accessing a network, for example, to authenticate and identify theUE215 as a subscriber of the network. Some examples of information stored at theSIM A210aand/orSIM B210bmay include, but not limited to, a subscriber identity such as an international mobile subscriber identity (IMSI) and/or information and/or key used to identify and authenticate theUE215 in a certain provider network. As an example, theUE215 may subscribe to a first operator and a second operator. That is, theUE215 may have afirst subscription212a(shown as SUB A) with the first operator and asecond subscription212b(shown as SUB B) with the second operator. Accordingly, theSIM A210amay store or maintain information for accessing a network of the first operator based on thefirst subscription212a, and theSIM B210bmay store information for accessing a network of the second operator based on thesecond subscription212b. In some instances, the first operator and the second operator may correspond to the same operator. For example, thefirst subscription212aand thesecond subscription212bmay correspond to different user accounts and/or services subscribed with the same operator. In other instances, the first operator may be different from the second operator.

In operation, theUE215 may communicate with aBS205a(operated by the first operator) using theSIM A210avia aradio link202a. Further, theUE215 may communicate with aBS205b(operated by the second operator) using theSIM B210bvia aradio link202b. In some aspects, theUE215 may use the same radio access technology (e.g., NR or NR-U) for communication with theBS205aand theBS205b. In other aspects, theUE215 may use one radio access technology (e.g., NR or NR-U) for communication with theBS205aand another radio access technology (e.g., LTE) for communication with theBS205b. AlthoughFIG.2 illustrates theUE215 communicates with different BSs205 using theSIM A210aand theSIM B210b, it should be understood that in other examples theUE215 may communicate with the same BS. For instance, theUE215 may communicate with thesame BS205afor thefirst subscription212avia theSIM A210aand for thesecond subscription212bvia theSIM B210b.

In some aspects, theUE215 may operate in a DSDS mode, where bothSIMs210aand210bcan be on standby (in an idle mode) waiting to begin communications. When a communication is established on one SIM (e.g., theSIM A210a), the other SIM (e.g., theSIM B210b) is no longer active. That is, one SIM may be active at a given time. For instance, both SIMs210 may share a single transceiver and/or RF chain at theUE215 for communications with corresponding network(s). In DSDA mode, bothSIMs210aand210bcan be active at the same time, as in the examples ofFIGS.4-6.

In some aspects, theradio link202abetween theUE215 and theBS205aand theradio link202bbetween theUE215 and theBS205bmay be over orthogonal bands such as FR1/FR2 or low band/high band FR1. Of course, any combination of radio links202 is possible, and the radio links may even take place using different radio access technologies. For instance,radio link202amay carry communications according to 5G protocols, whereasradio link202bmay carry communications according to LTE protocols.

Furthermore,UE215 may manage DMRS bundling for DSDA operation, according to the techniques described below with respect toFIGS.7-9.

FIG.3 illustrates an example hardware architecture for RF chains, which may be implemented within UE115 (FIG.1), UE215 (FIG.2), or UE1000 (FIG.10). In this exemplary design, the hardware architecture includes atransceiver320 coupled to afirst antenna310, atransceiver322 coupled to asecond antenna312, and a data processor/controller380.Transceiver320 includes multiple (K) receivers330pato330pkand multiple (K) transmitters350pato350pkto support multiple frequency bands, multiple radio technologies, carrier aggregation, etc.Transceiver322 includes L receivers330sato330s1 and L transmitters350sato350s1 to support multiple frequency bands, multiple radio technologies, carrier aggregation, receive diversity, multiple-input multiple-output (MIMO) transmission from multiple transmit antennas to multiple receive antennas, etc.

In the exemplary design shown inFIG.3, each receiver330 includes an LNA340 and receive circuits342. For data reception,antenna310 receives signals from base stations and/or other transmitter stations and provides a received RF signal, which may be routed through anantenna interface circuit324 and presented as an input RF signal to a selected receiver.Antenna interface circuit324 may include switches, duplexers, transmit filters, receive filters, matching circuits, etc. The description below assumes that receiver330pais the selected receiver, though the described operations apply equally well to any of the other receivers330. Within receiver330pa, an LNA340paamplifies the input RF signal and provides an output RF signal. Receive circuits342padownconvert the output RF signal from RF to baseband, amplify and filter the downconverted signal, and provide an analog input signal todata processor380. Receive circuits342pamay include mixers, filters, amplifiers, matching circuits, an oscillator, a local oscillator (LO) generator, a phase locked loop (PLL), etc. Each remaining receiver330 intransceivers320 and322 may operate in a similar manner as receiver330pa.

In the exemplary design shown inFIG.3, each transmitter350 includes transmit circuits352 and a power amplifier (PA)354. For data transmission,data processor380 processes (e.g., encodes and modulates) data to be transmitted and provides an analog output signal to a selected transmitter. The description below assumes that transmitter350pais the selected transmitter, though the described operations apply equally well to any of the other transmitters350. Within transmitter350pa, transmit circuits352paamplify, filter, and upconvert the analog output signal from baseband to RF and provide a modulated RF signal. Transmit circuits352pamay include amplifiers, filters, mixers, matching circuits, an oscillator, an LO generator, a PLL, etc. A PA354pareceives and amplifies the modulated RF signal and provides a transmit RF signal having the proper output power level. The transmit RF signal may be routed throughantenna interface circuit324 and transmitted viaantenna310. Each remaining transmitter350 intransceivers320 and322 may operate in a similar manner as transmitter350pa.

FIG.3 shows an exemplary design of receiver330 and transmitter350. A receiver and a transmitter may also include other circuits not shown inFIG.3, such as filters, matching circuits, etc. All or a portion oftransceivers320 and322 may be implemented on one or more analog (ICs, RF ICs (RFICs), mixed-signal ICs, etc. For example, LNAs340 and receive circuits342 withintransceivers320 and322 may be implemented on multiple IC chips or on the same IC chip. The circuits intransceivers320 and322 may also be implemented in other manners.

Data processor/controller380 may perform various functions for wireless device110. For example,data processor380 may perform processing for data being received via receivers330 and data being transmitted via transmitters350.Controller380 may control the operation of the various circuits withintransceivers320 and322. Amemory382 may store program codes and data for data processor/controller380. Data processor/controller380 may be implemented on one or more application specific integrated circuits (ASICs) and/or other ICs.

Controller380 may be in communication with one or more SIMs to provide DSDA operation in which both SIMs may be in active mode at the same time. Thecontroller380 may execute software logic that assigns one of thetransceivers320,322 to a particular SIM and the other one of the transceivers to the other SIM in a dual SIM implementation. In another example, thecontroller380 may assign bothtransceivers320,322 to both SIMs, thereby allowing both SIMs to employ multi-antenna operations, such as beam forming and the like. In one example implementation, one of the SIMs is active, whereas the other SIM is in idle mode. During an SRS occurrence, the first SIM (e.g., the DDS) may use the transmitting portions of either or both of thetransceivers320,322 to transmit an SRS. The network may then use received SRS to estimate the DL channel for the RX ports (e.g., antenna/transceiver pairs) of the UE.

In some examples, the transmit hardware may be configured by the network for UL on certain frequency bands that may be associated with TX sharing. For instance, if the first SIM and the second SIM are both configured for UL on the upper range of FR1 or both on the lower range of FR1, then the first SIM and the second SIM may rely on the same filters, oscillators, or other hardware and, thus, may be forced into TX sharing.

An example is shown intimeline400 ofFIG.4, where a first SIM, associated with a first subscription (Sub 1) has a higher priority (HP) than does the second SIM that is associated with a second subscription (Sub 2). UL transmissions401-403 may proceed, whereas the UE would not be able to performUL transmissions404 and405 overlapping in time because of transmit hardware sharing. In this instance,UL transmission405 is canceled becauseUL transmission404 has higher priority. Transmit hardware sharing (TX sharing) band combinations may be incompatible with DMRS because those band combinations may cause the transmit hardware to dynamically retune from one band to the other, thereby potentially losing phase coherence. If the UE loses phase coherence across multiple DMRS symbols, the network may incorrectly estimate the channel of the UE's receiver, thereby resulting in performance deterioration. Implementations described herein may advertise a lack of capability to support DMRS bundling when band combinations would otherwise cause TX sharing. Other implementations described herein may enable and disable DMRS bundling semi-statically so that DMRS bundling can be used when band combinations are not associated with TX sharing and avoided when band combinations are associated with TX sharing.

In another example, if the first SIM is configured for UL on FR1, and the second SIM is configured for UL on FR2, then the first SIM and the second SIM may use separate filters, oscillators, and the like, thereby allowing for full concurrency. Similarly, some implementations may allow for full concurrency with one SIM on a high band of FR1 and the other SIM on a lower band of FR1. Of course, these are just examples, and the scope of implementations is not limited to any particular band combination nor any particular hardware combination that may or may not allow for full concurrency. An example of full concurrency is shown intimeline500 ofFIG.5, in which transmissions501-505 may proceed, and eventransmissions504 and505 may proceed without interruption because the particular band combination is not associated with TX sharing.

In another example, a UL transmission by the second SIM may potentially interfere with a DL reception by the first SIM. For instance, some frequency bands are close together and may be difficult for the RF receive filters to attenuate when received at full power from transmit hardware. Such frequency bands may be associated with coexistence, where theprocessor380 is programmed to reduce a power of the transmit signal by the second SIM during a receive operation by the first SIM. An example is shown intimeline600 ofFIG.6, which illustratesexample UL transmissions601,603,605 andexample DL receptions602,604. The power ofUL transmission605 is reduced (backed off) to provide coexistence by reducing potential interference withDL reception604. However, reducing transmit power has the potential to cause loss of phase coherence.

Returning toFIG.3, theprocessor380 may be programmed to control the hardware ofFIG.3 to accommodate DMRS bundling according to the actions described below with respect toFIGS.7-9 and according to the context described with respect toFIGS.4-6.

FIG.7 is a flowchart of amethod700 to adjust increase performance in a multi-SIM system that supports DSDA and DMRS bundling, according to some aspects of the present disclosure. Themethod700 may be performed by UE, such as UE115 (FIG.1), UE215 (FIG.2), or UE1000 (FIG.10). As illustrated, themethod700 includes a number of enumerated actions, but aspects of themethod700 may include additional actions before, after, and in between the enumerated actions. In some aspects, one or more of the enumerated actions may be omitted or performed in a different order.

Ataction701, the UE receives information indicating a first band for use with the first SIM and indicating a second band for use with the second SIM. For instance, the information may be received from a network that configures the UE to perform UL operations on specified frequency bands. In another example, the information may be received from an application that can predict possible DSDA band combinations that would be exercised in the current location or an upcoming predicted route. For instance, the application may include a trained machine learning algorithm that predicts DSDA band combinations from any of a variety of inputs, such as current location, operators serving the different SIMs, direction of travel, and the like. In any event, the processor of the UE may have information of a frequency band combination, with a first frequency band corresponding to the first SIM and a second frequency band corresponding to the second SIM.

Ataction702, the UE determines that the first frequency band and the second frequency band are incompatible with DMRS bundling during a DSDA operating mode. For instance, the UE may recognize that the first band and the second band are associated with a transmitter tune away from the first SIM to the second SIM, such as described above with respect toFIG.4. In other words, the hardware of the UE may not support simultaneous operation in the first band and the second band.

In yet another example, the UE may determine that the first band and the second band are associated with a transmitter power back off of either the first SIM or the second SIM. An example is given above with respect toFIG.6. Of course, these are just examples, and the scope of implementations may include any determination of incompatible bands, including any combination of bands that might cause the UE to perform an operation that would cause loss of phase coherency during a DMRS bundling operation.

Ataction703, the UE informs a network base station, which interacts with the first SIM, that DMRS bundling is unavailable at the UE. Various examples of informing the base station of DMRS bundling unavailability include advertising a lack of DMRS bundling capability, requesting that the base station disable DMRS bundling for either the first SIM or the second SIM, and the like.

For instance, in an example in which the UE advertises a lack of DMRS bundling capability, the UE may performaction703 at any appropriate time. In one implementation, the UE may performaction703 upon entering DSDA mode. The UE may employee a tracking area update (TAU) procedure to cause the network to re-query UE capability, at which point the UE advertises its lack of capability for DMRS bundling upon entering DSDA mode. However, the UE may performaction703 at other times, such as upon completion ofaction702, whether or not, or even before, the UE has entered DSDA mode.

In an example in which the UE requests that the base station disable DMRS bundling,action703 may be performed in any of a variety of ways. In some implementations, there may be a defined semi-static procedure for the UE to request enabling and disabling DMRS bundling over multiple TBs. For instance, the UE may employ an information element (IE) in a UE assistance information (UAI) message to request enabling or disabling DMRS bundling. For instance, the UE may performaction703 upon determining that a band combination (either predicted or configured) is incompatible with frequency coherence required for DMRS bundling. The UE may, accordingly, send a UAI message to request that DMRS bundling be disabled.

Although not explicitly shown inFIG.7, in subsequent usage one or both of the frequency bands may be replaced by other frequency bands that are compatible with DMRS bundling and maintaining frequency coherence. In such an instance, the UE may determine that DMRS bundling is appropriate with the new frequency band combination and send a further UAI message to the network to request enabling DMRS bundling.

The actions701-703 may be repeated as often as appropriate. For instance, as the UE moves from one base station to another base station, configurations may be changed, including a combination of frequency bands, and DSDA may be turned on or off. Accordingly, the UE may perform the actions described above to avoid being configured to perform DMRS bundling when the frequency band combination is incompatible with DMRS bundling, and the UE may also re-enabled DMRS bundling at appropriate times.

Various embodiments may provide advantages over prior systems. For instance, embodiments may perform DMRS bundling when phase coherence can be maintained and avoid performing DMRS bundling when phase coherence may not be maintained. Therefore, the UE may provide the network with more appropriate DMRSs for the network to measure the receive channel and to configure DL operation of the UE. As a result, those systems may increase throughput, thereby increasing data per battery charge efficiency and data per time efficiency. Furthermore, such systems may also increase user satisfaction by having faster download times.

FIG.8 is a flowchart of amethod800 to adjust increase performance in a multi-SIM system that supports DSDA and DMRS bundling, according to some aspects of the present disclosure. Themethod800 may be performed by UE, such as UE115 (FIG.1), UE215 (FIG.2), or UE1000 (FIG.10). As illustrated, themethod800 includes a number of enumerated actions, but aspects of themethod800 may include additional actions before, after, and in between the enumerated actions. In some aspects, one or more of the enumerated actions may be omitted or performed in a different order.

Method800 may be performed in a TX sharing scenario as well as in a full concurrency with coexistence scenario. For instance, in a TX sharing scenario, transmit hardware sharing and the associated transmit switching between the two SIMs is controlled by a TDM based priority pattern. In one implementation, the UE may defer a priority switch from the first SIM to the second SIM (e.g., a transmit hardware switch) until the end of a current DMRS bundling repetition being performed by the first SIM. Once this is done for the first SIM, the same may be done for the other SIM if both of the SIMs are configured with DMRS bundling. In other words, if an amount of time that one SIM has a higher priority state is extended, then a same or similar amount of time may be added to the higher priority state for the other SIM. This may help to ensure that transmit hardware resources are shared between the two SIMs based on the configured repetition pattern or transmission over multiple TBs, such that a given DMRS bundle is transmitted without having any issue on either SIM.

Now looking to an example in which there is full concurrency with coexistence,method800 is similar. As discussed above with respect toFIG.6, full concurrency with coexistence may include backing off transmit power when the transmit power of one SIM would interfere with reception by the other SIM having a higher priority state. Vice versa is also possible—reception for one SIM may be blanked or performed according to best efforts when that SIM is in a lower priority state than a transmitting SIM. In this example, the decision to either back off transmit power or blank a reception is based on a TDM priority pattern. If the priority state change would change the priority of an aggressor in a coexistence-impacted band combination, various implementations may be made to defer the change of the priority state until the current repetition of DMRS bundling is complete. The additional time added to the aggressor SIM may then be used to extend the high priority state of the other SIM by the same or similar duration to achieve a same or similar time ratio of priority between the two SIMs.

In any event, whethermethod800 is performed in a TX sharing scenario or in a full concurrency with coexistence scenario,method800 may help to ensure that DMRS bundling is complete by one SIM before taking an action that would result in loss of phase coherence for the other SIMs.Method800 may also be used to provide an amount of fairness between the two SIMs by switching priority between the two SIMs and attempting to add a same or similar amount of time to a high priority state of both SIMs over time.

Ataction801, the UE operates in a DSDA mode with respect to a first SIM and a second SIM. Ataction802, the UE controls transmit operations of the first SIM and the second SIM according to a time division duplex priority pattern. For instance, the priority pattern may shift a priority state from one SIM to the other SIM periodically. In a TX sharing scenario, higher priority state may indicate that a given SIM may use TX hardware before having to share that TX hardware with the other SIM. In a full concurrency with coexistence scenario, a higher priority state may indicate that a given SIM may not have to reduce its transmit power or blank its reception on account of a transmission reception by the other SIM.

Ataction803, the first SIM has a higher priority state according to the TDM priority pattern. The first SIM performs a DMRS bundling operation, which may include the first SIM transmitting multiple DMRSs over different time instants, perhaps even over multiple TBs, corresponding to different UL transmissions (e.g., PUSCH transmissions and/or PUCCH transmissions) and with coherent phase.

Ataction804, the TDM priority pattern may indicate that priority should be switched from the first SIM to the second SIM. However,action804 includes deferring a priority switch for an amount of time corresponding to the first SIM reaching completion of a repetition of DMRS bundling. Put another way, the priority switch may be deferred until the first SIM has completed its repetition of DMRS bundling.

The scope of implementations is not limited to the specific actions shown inFIG.8.Action804 may further include performing the priority switch to give the higher priority state to the second SIM and then adding time to the higher priority state as applied to the second SIM in compensation for deferring the priority switch. Switching may be performed back-and-forth from the first SIM to the second SIM and back to the first SIM multiple times over during operation. Also, when time is added to a higher priority state of one SIM, a similar amount of time may be added to the other SIM for its higher priority state.

Also, the scope of implementations may include the capability to determine to make the priority switch during DMRS bundling by one SIM if that SIM has completed less than a threshold amount of the DMRS bundling repetition. The threshold may be set at any appropriate amount, such as 10%, 20%, or the like. In a particular example, when the priority pattern indicates that priority should switch from the first SIM to the second SIM, the UE may compare a progress of the DMRS bundling repetition to the threshold and, if the progress is below the threshold, may switch the priority to the other SIM.Method800 may then include allowing the first SIM to complete a DMRS bundling repetition in the next scheduled DMRS bundling repetition.

FIG.9 is a flowchart of amethod900 to adjust increase performance in a multi-SIM system that supports DSDA and DMRS bundling, according to some aspects of the present disclosure. Themethod900 may be performed by UE, such as UE115 (FIG.1), UE215 (FIG.2), or UE1000 (FIG.10). As illustrated, themethod900 includes a number of enumerated actions, but aspects of themethod900 may include additional actions before, after, and in between the enumerated actions. In some aspects, one or more of the enumerated actions may be omitted or performed in a different order.

Method900 is performed in the context of a full concurrency with coexistence scenario. Specifically, a higher priority state may be switched from one SIM to the other SIM according to a TDM priority pattern, even if one SIM is performing a DMRS bundling repetition. The switch in priority may be accompanied by compensation measures that maintain phase coherency, even in a SIM that is currently transmitting and is caused to perform transmit power back off.

Actions901-903 are the same as or similar to actions801-803 ofFIG.8.

Now looking toaction904, it includes switching the higher priority state from the first SIM to the second SIM during DMRS bundling on the first SIM. Ataction905, the UE reduces the transmit power of the first SIM during the DMRS bundling on the first SIM. This is in response to switching the higher priority state from the first SIM to the second SIM. However, the UE maintains a phase continuity of the first SIM.

Phase continuity may be maintained in any appropriate manner. In one implementation, the UE may reduce the transmit power of the first SIM by applying filter output scaling in the baseband without changing analog gain. An amount of filter output scaling that may be used to reach the goal of maintaining phase continuity may be determined from simulation or experimentation and then stored in memory of the UE for multiple conditions and multiple output scaling values. In another implementation, the UE may lower a power amplifier state to reduce the transmit power while at the same time applying phase compensation in the RF portion of the transmit chain. Such implementation may be seen as a coarse adjustment for transmit back off, but it may still provide for phase coherence maintenance. These are just examples, and compensation may be applied anywhere that is appropriate in the transmit chain, whether in a baseband portion or a RF portion. Once again, an amount of compensation that may be used may be determined from simulation or experimentation and then stored in memory of the UE for multiple conditions and multiple power reduction values.

An advantage of themethod900 may include providing less interruption to DMRS bundling, thereby allowing for better channel estimation at the network and, therefore, higher UL throughput for the UE.

FIG.10 is a block diagram of an exemplary UE1000 according to some aspects of the present disclosure. The UE1000 may be aUE115 orUE215 as discussed above inFIGS.1-2 and may conform to the hardware architecture described above with respect toFIG.3. As shown, the UE1000 may include aprocessor1002, amemory1004, amulti-SIM module1008, atransceiver1010 including amodem subsystem1012 and a radio frequency (RF)unit1014, and one ormore antennas1016. These elements may be coupled with one another. The term “coupled” may refer to directly or indirectly coupled or connected to one or more intervening elements. For instance, these elements may be in direct or indirect communication with each other, for example via one or more buses.

Theprocessor1002 may include a central processing unit (CPU), a digital signal processor (DSP), an application specific integrated circuit (ASIC), a controller, a field programmable gate array (FPGA) device, another hardware device, a firmware device, or any combination thereof configured to perform the operations described herein. Theprocessor1002 may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.

Thememory1004 may include a cache memory (e.g., a cache memory of the processor1002), random access memory (RAM), magnetoresistive RAM (MRAM), read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read only memory (EPROM), electrically erasable programmable read only memory (EEPROM), flash memory, solid state memory device, hard disk drives, other forms of volatile and non-volatile memory, or a combination of different types of memory. In an aspect, thememory1004 includes a non-transitory computer-readable medium. Thememory1004 may store, or have recorded thereon,instructions1006. Theinstructions1006 may include instructions that, when executed by theprocessor1002, cause theprocessor1002 to perform the operations described herein with reference to aUE115,215 in connection with aspects of the present disclosure, for example, aspects ofFIGS.1-9.Instructions1006 may also be referred to as code, which may include any type of computer-readable statements.

Themulti-SIM module1008 may be implemented via hardware, software, or combinations thereof. For example, themulti-SIM module1008 may be implemented as a processor, circuit, and/orinstructions1006 stored in thememory1004 and executed by theprocessor1002.

In some aspects, themulti-SIM module1008 may include multiple SIMs or SIM cards (e.g., 2, 3, 4, or more) similar to the SIMs210. Each SIM may be configured to store information used for accessing a network, for example, to authenticate and identify the UE1000 as a subscriber of the network. Some examples of information stored on a SIM may include, but not limited to, a subscriber identity such as an international mobile subscriber identity (IMSI) and/or information and/or key used to identify and authenticate the UE1000 in a certain provider network. In some aspects, the UE1000 may have a first subscription on a first SIM of the multiple SIMs and a second subscription on a second SIM of the multiple SIMs. The first subscription may identify the UE1000 by a first subscriber identity, and the second subscription may identify the UE1000 by a second subscriber identity.

In some embodiments, the functionality described above with respect toFIGS.7-9 may be included as logic withinmulti-SIM module1008. Other embodiments, the functionality may be included in another component, such as in computer readable code withininstructions1006 inmemory1004.

As shown, thetransceiver1010 may include themodem subsystem1012 and theRF unit1014. Thetransceiver1010 can be configured to communicate hi-directionally with other devices, such as theBSs105 and1100. Themodem subsystem1012 may be configured to modulate and/or encode the data from thememory1004 and themulti-SIM module1008 according to a modulation and coding scheme (MCS), e.g., a low-density parity check (LDPC) coding scheme, a turbo coding scheme, a convolutional coding scheme, a digital beamforming scheme, etc. TheRF unit1014 may be configured to process (e.g., perform analog to digital conversion or digital to analog conversion, etc.) modulated/encoded data (e.g., PUSCH data, PUCCH UCI, MSG1, MSG3, etc.) or of transmissions originating from another source such as aUE115, a BS105, or an anchor. TheRF unit1014 may be further configured to perform analog beamforming in conjunction with digital beamforming. Although shown as integrated together intransceiver1010, themodem subsystem1012 and theRF unit1014 may be separate devices that are coupled together at the UE1000 to enable the UE1000 to communicate with other devices.

TheRF unit1014 may provide the modulated and/or processed data, e.g. data packets (or, more generally, data messages that may contain one or more data packets and other information), to theantennas1016 for transmission to one or more other devices. Theantennas1016 may further receive data messages transmitted from other devices. Theantennas1016 may provide the received data messages for processing and/or demodulation at thetransceiver1010. Thetransceiver1010 may provide the demodulated and decoded data (e.g., RRC configurations, MIB. PDSCH data and/or PDCCH DCIs, etc.) to themulti-SIM module1008 for processing. Theantennas1016 may include multiple antennas of similar or different designs in order to sustain multiple transmission links.

In an aspect, the UE1000 can includemultiple transceivers1010 implementing different RATs (e.g., NR and LTE). In an aspect, the UE1000 can include asingle transceiver1010 implementing multiple RATs (e.g., NR and LTE). In an aspect, thetransceiver1010 can include various components, where different combinations of components can implement different RATs.

FIG.11 is a block diagram of anexemplary BS1100 according to some aspects of the present disclosure. TheBS1100 may be a BS105 or a BS205 as discussed inFIGS.1 and2. As shown, theBS1100 may include aprocessor1102, amemory1104, acommunication module1108, atransceiver1110 including amodem subsystem1112 and aRF unit1114, and one ormore antennas1116. These elements may be coupled with one another. The term “coupled” may refer to directly or indirectly coupled or connected to one or more intervening elements. For instance, these elements may be in direct or indirect communication with each other, for example via one or more buses.

Theprocessor1102 may have various features as a specific-type processor. For example, these may include a CPU, a DSP, an ASIC, a controller, a FPGA device, another hardware device, a firmware device, or any combination thereof configured to perform the operations described herein. Theprocessor1102 may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.

Thememory1104 may include a cache memory (e.g., a cache memory of the processor1102), RAM, MRAM, ROM, PROM, EPROM, EEPROM, flash memory, a solid state memory device, one or more hard disk drives, memristor-based arrays, other forms of volatile and non-volatile memory, or a combination of different types of memory. In some aspects, thememory1104 may include a non-transitory computer-readable medium. Thememory1104 may storeinstructions1106. Theinstructions1106 may include instructions that, when executed by theprocessor1102, cause theprocessor1102 to perform operations described herein, for example, aspects ofFIGS.1 and2.Instructions1106 may also be referred to as program code. The program code may be for causing a wireless communication device to perform these operations, for example by causing one or more processors (such as processor1102) to control or command the wireless communication device to do so. The terms “instructions” and “code” should be interpreted broadly to include any type of computer-readable statement(s). For example, the terms “instructions” and “code” may refer to one or more programs, routines, sub-routines, functions, procedures, etc. “Instructions” and “code” may include a single computer-readable statement or many computer-readable statements.

Thecommunication module1108 may be implemented via hardware, software, or combinations thereof. For example, thecommunication module1108 may be implemented as a processor, circuit, and/orinstructions1106 stored in thememory1104 and executed by theprocessor1102. In some examples, thecommunication module1108 can be integrated within themodem subsystem1112. For example, thecommunication module1108 can be implemented by a combination of software components (e.g., executed by a DSP or a general processor) and hardware components (e.g., logic gates and circuitry) within themodem subsystem1112. Thecommunication module1108 may communicate with one or more components ofBS1100 to implement various aspects of the present disclosure, for example, aspects ofFIGS.1 and2.

As shown, thetransceiver1110 may include themodem subsystem1112 and theRF unit1114. Thetransceiver1110 can be configured to communicate bi-directionally with other devices, such as theUEs115,215 and/orBS1100 and/or another core network element. Themodem subsystem1112 may be configured to modulate and/or encode data according to a MCS, e.g., a LDPC coding scheme, a turbo coding scheme, a convolutional coding scheme, a digital beamforming scheme, etc. TheRF unit1114 may be configured to process (e.g., perform analog to digital conversion or digital to analog conversion, etc.) modulated/encoded data (e.g., RRC configurations, MIB, PDSCH data and/or PDCCH DCIs, etc.) from the modem subsystem1112 (on outbound transmissions) or of transmissions originating from another source such as aUE115,215, and/or UE1000. TheRF unit1114 may be further configured to perform analog beamforming in conjunction with the digital beamforming. Although shown as integrated together intransceiver1110, themodem subsystem1112 and/or theRF unit1114 may be separate devices that are coupled together at theBS1100 to enable theBS1100 to communicate with other devices.

TheRF unit1114 may provide the modulated and/or processed data, e.g. data packets (or, more generally, data messages that may contain one or more data packets and other information), to theantennas1116 for transmission to one or more other devices. Theantennas1116 may further receive data messages transmitted from other devices and provide the received data messages for processing and/or demodulation at thetransceiver1110. Thetransceiver1110 may provide the demodulated and decoded data (e.g., PUSCH data, PUCCH UCI, MSG1, MSG3, etc.) to thecommunication module1108 for processing. Theantennas1116 may include multiple antennas of similar or different designs in order to sustain multiple transmission links.

In an aspect, theBS1100 can includemultiple transceivers1110 implementing different RATs (e.g., NR and LTE). In an aspect, theBS1100 can include asingle transceiver1110 implementing multiple RATs (e.g., NR and LTE). In an aspect, thetransceiver1110 can include various components, where different combinations of components can implement different RATs.

Further aspects of the present disclosure include the following clauses:

1. A user equipment (UE) comprising:

• • a first subscriber identity module (SIM) associated with a first service provider subscription and a second SIM associated with a second service provider subscription; and
  • a processor configured to access the first SIM and the second SIM, wherein the processor is further configured to:
    • receiving information indicating a first band for use with the first SIM and a second band for use with the second SIM;
    • determining that the first hand and the second band are incompatible with demodulation reference signal (DMRS) bundling in a Dual SIM Dual Active (DSDA) operating mode; and
    • informing a base station, interacting with the first SIM, that DMRS bundling is unavailable at the UE.

2. The UE of clause 1, wherein the processor is further configured to receive the information indicating the first band from a machine learning algorithm providing a prediction.

3. The UE of clause 1, wherein the processor is further configured to receive the information indicating the first band from the base station.

4. The UE of any of clauses 1-3, wherein the processor is configured to inform the base station that DMRS bundling is unavailable before entering the DSDA operating mode.

5. The UE of any of clauses 1-3, wherein the processor is configured to inform the base station that DMRS bundling is unavailable upon entering the DSDA operating mode.

6. The UE of any of clauses 1-5, wherein the processor is configured to inform the base station that DMRS bundling is unavailable by initiating a tracking area update (TAU) operation and advertising a lack of capability in response to a network re-query.

7. The UE of any of clauses 1-6, wherein the processor is configured to inform the base station that DMRS bundling is unavailable via an information element (IE) in a UE assistance information (UAI) message.

8. The UE of clause 7, wherein the processor is further configured to determine that a subsequent band combination for the first SIM and the second SIM is compatible with DMRS bundling and to inform the base station that DMRS bundling is available via the IE.

9. The UE of any of clauses 1-8, wherein the processor is configured to determine that the first band and the second band are incompatible with DMRS bundling by determining that the first band and the second band are associated with a transmitter tune away from the first SIM to the second SIM.

10. The UE of any of clauses 1-9, wherein the processor is configured to determine that the first band and the second band are incompatible with DMRS bundling by determining that the first band and the second band do not support simultaneous transmission operation within transmit hardware of the UE.

11. The UE of any of clauses 1-10, wherein the processor is configured to determine that the first band and the second band are incompatible with DMRS bundling by determining that the first band and the second band are associated with a transmitter power back off of either the first SIM or the second SIM.

12. A method of wireless communication performed by a user equipment (UE), the method comprising:

• • operating in a Dual SIM Dual Active (DSDA) mode with respect to a first subscriber identity module (SIM) and a second SIM;
  • controlling transmit operations of the first SIM and the second SIM according to a time division multiplexed (TDM) priority pattern;
  • performing demodulation reference signal (DMRS) bundling on the first SIM, the first SIM having a higher priority state according to the TDM priority pattern; and
  • deferring a priority switch to give the higher priority state to the second SIM until after the first SIM has completed a repetition of DMRS bundling.

13. The method of clause 12, wherein the first SIM and the second SIM share transmission hardware resources of the UE, wherein the first SIM transmits according to a first band and the second SIM transmits according to a second band that is incompatible with simultaneous operation by the transmission hardware resources.

14. The method of any of clauses 12-13, wherein the first SIM transmits according to a first band, and wherein the second SIM receives according to a second band, and further wherein a combination of the first band and the second band is associated with a backoff of transmit power of the first SIM.

15. The method of any of clauses 12-14, wherein the first SIM transmits according to a first band, and wherein the second SIM receives according to a second band, and further wherein a combination of the first band and the second band is associated with a blank receive operation of the second SIM.

16. The method of any of clauses 12-15, further comprising:

• • performing the priority switch to give the higher priority state to the second SIM; and
  • adding time to the higher priority state as applied to the second SIM in compensation for deferring the priority switch.

17. The method of any of clauses 12-16, further comprising:

• • performing a subsequent priority switch to give the higher priority state to the second SIM in response to the first SIM having completed less than a threshold amount of a DMRS bundling repetition.

18. A non-transitory computer-readable medium having program code recorded thereon for wireless communication by a user equipment (UE), the program code comprising:

• • code for operating in a Dual SIM Dual Active (DSDA) mode with respect to a first subscriber identity module (SIM) and a second SIM;
  • code for controlling transmit operations of the first SIM and the second SIM according to a time division multiplexed (TDM) priority pattern;
  • code for performing demodulation reference signal (DMRS) bundling on the first SIM, the first SIM having a higher priority state according to the TDM priority pattern; and
  • code for switching the higher priority state to the second SIM during the DMRS bundling on the first SIM; and
  • code for reducing a transmit power of the first SIM during the DMRS bundling on the first SIM, including maintaining phase continuity of the first SIM.

19. The non-transitory computer-readable medium of clause 18, further comprising: code for scaling a filter output in baseband, associated with the first SIM, wherein scaling the filter output includes compensating a phase of operation of the first SIM in accordance with reducing the transmit power.

20. The non-transitory computer-readable medium of any of clauses 18-19, further comprising:

• • code for lowering a power amplifier state to reduce the transmit power; and
  • code for compensating a phase of operation of the first SIM in accordance with lowering the power amplifier state.

21. A user equipment (UE) comprising:

• • means for receiving information indicating a first band for use with a first subscriber identity module (SIM) and a second band for use with a second SIM;
  • means for determining that the first band and the second band are incompatible with demodulation reference signal (DMRS) bundling in a Dual SIM Dual Active (DSDA) operating mode; and
  • means for taking an action with respect to DMRS bundling in response to determining that the first band and the second band are incompatible with DMRS bundling, including either one or both of: means for advertising a lack of capability for DMRS bundling and means for requesting that DMRS bundling be disabled.

22. The UE of clause 21, further comprising means for determining that that the first band and the second band are associated with a transmitter tune away from the first SIM to the second SIM.

23. The UE of any of clauses 21-22, further comprising means for determining that the first band and the second band do not support simultaneous transmission operation within transmit hardware of the UE.

24. The UE of any of clauses 21-23, further comprising means for determining that the first band and the second band are associated with a transmitter power back off of either the first SIM or the second SIM.

The various illustrative blocks and modules described in connection with the disclosure herein may be implemented or performed with a general-purpose processor, a DSP, an ASIC, an FPGA or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general-purpose processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices (e.g., a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration).

The functions described herein may be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Other examples and implementations are within the scope of the disclosure and appended claims. For example, due to the nature of software, functions described above can be implemented using software executed by a processor, hardware, firmware, hardwiring, or combinations of any of these. Features implementing functions may also be physically located at various positions, including being distributed such that portions of functions are implemented at different physical locations. Also, as used herein, including in the claims, “or” as used in a list of items (for example, a list of items prefaced by a phrase such as “at least one of” or “one or more of”) indicates an inclusive list such that, for example, a list of [at least one of A, B, or C] means A or B or C or AB or AC or BC or ABC (i.e., A and B and C).

As those of some skill in this art will by now appreciate and depending on the particular application at hand, many modifications, substitutions and variations can be made in and to the materials, apparatus, configurations and methods of use of the devices of the present disclosure without departing from the spirit and scope thereof. In light of this, the scope of the present disclosure should not be limited to that of the particular aspects illustrated and described herein, as they are merely by way of some examples thereof, but rather, should be fully commensurate with that of the claims appended hereafter and their functional equivalents.

Claims (17)

What is claimed is:

1. A user equipment (UE) comprising:

a first subscriber identity module (SIM) associated with a first service provider subscription and a second SIM associated with a second service provider subscription; and

a processor configured to access the first SIM and the second SIM, wherein the processor is further configured to:

operate in a Dual SIM Dual Active (DSDA) mode with respect to the first SIM and the second SIM;

control transmit operations of the first SIM and the second SIM according to a time division multiplexed (TDM) priority pattern;

perform demodulation reference signal (DMRS) bundling on the first SIM, the first SIM having a higher priority state according to the TDM priority pattern; and

switch the higher priority state to the second SIM during the DMRS bundling on the first SIM;

reduce a transmit power of the first SIM during the DMRS bundling on the first SIM, including maintaining phase continuity of the first SIM;

scale a filter output in baseband, associated with the first SIM, wherein scaling the filter output includes compensating a phase of operation of the first SIM in accordance with reducing the transmit power;

lower a power amplifier state to reduce the transmit power;

compensate a phase of operation of the first SIM in accordance with lowering the power amplifier state;

receiving information indicating a first band for use with the first SIM and a second band for use with the second SIM;

determining that the first band and the second band are incompatible with demodulation reference signal (DMRS) bundling in a Dual SIM Dual Active (DSDA) operating mode; and

informing a base station that DMRS bundling is unavailable at the UE.

2. The UE ofclaim 1, wherein the processor is further configured to receive the information indicating the first band from a machine learning algorithm providing a prediction.

3. The UE ofclaim 1, wherein the processor is further configured to receive the information indicating the first band from the base station.

4. The UE ofclaim 1, wherein the processor is configured to inform the base station that DMRS bundling is unavailable before entering the DSDA operating mode.

5. The UE ofclaim 1, wherein the processor is configured to inform the base station that DMRS bundling is unavailable upon entering the DSDA operating mode.

6. The UE ofclaim 1, wherein the processor is configured to inform the base station that DMRS bundling is unavailable by initiating a tracking area update (TAU) operation and advertising a lack of capability in response to a network re-query.

7. The UE ofclaim 1, wherein the processor is configured to inform the base station that DMRS bundling is unavailable via an information element (IE) in a UE assistance information (UAI) message.

8. The UE ofclaim 7, wherein the processor is further configured to determine that a subsequent band combination for the first SIM and the second SIM is compatible with DMRS bundling and to inform the base station that DMRS bundling is available via the IE.

9. The UE ofclaim 1, wherein the processor is configured to determine that the first band and the second band are incompatible with DMRS bundling by determining that the first band and the second band are associated with a transmitter tune away from the first SIM to the second SIM.

10. The UE ofclaim 1, wherein the processor is configured to determine that the first band and the second band are incompatible with DMRS bundling by determining that the first band and the second band do not support simultaneous transmission operation within transmit hardware of the UE.

11. The UE ofclaim 1, wherein the processor is configured to determine that the first band and the second band are incompatible with DMRS bundling by determining that the first band and the second band are associated with a transmitter power back off of either the first SIM or the second SIM.

12. A method of wireless communication performed by a user equipment (UE), the method comprising:

operating in a Dual SIM Dual Active (DSDA) mode with respect to a first subscriber identity module (SIM) and a second SIM;

controlling transmit operations of the first SIM and the second SIM according to a time division multiplexed (TDM) priority pattern;

performing demodulation reference signal (DMRS) bundling on the first SIM, the first SIM having a higher priority state according to the TDM priority pattern;

switching the higher priority state to the second SIM during the DMRS bundling on the first SIM;

reducing a transmit power of the first SIM during the DMRS bundling on the first SIM, including maintaining phase continuity of the first SIM;

scaling a filter output in baseband, associated with the first SIM, wherein scaling the filter output includes compensating a phase of operation of the first SIM in accordance with reducing the transmit power;

lowering a power amplifier state to reduce the transmit power;

compensating a phase of operation of the first SIM in accordance with lowering the power amplifier state; and

deferring a priority switch to give the higher priority state to the second SIM until after the first SIM has completed a repetition of DMRS bundling.

13. The method ofclaim 12, wherein the first SIM and the second SIM share transmission hardware resources of the UE, wherein the first SIM transmits according to a first band and the second SIM transmits according to a second band that is incompatible with simultaneous operation by the transmission hardware resources.

14. The method ofclaim 12, wherein the first SIM transmits according to a first band, and wherein the second SIM receives according to a second band, and further wherein a combination of the first band and the second band is associated with a backoff of transmit power of the first SIM.

15. The method ofclaim 12, wherein the first SIM transmits according to a first band, and wherein the second SIM receives according to a second band, and further wherein a combination of the first band and the second band is associated with a blank receive operation of the second SIM.

16. The method ofclaim 12, further comprising:

performing the priority switch to give the higher priority state to the second SIM; and

adding time to the higher priority state as applied to the second SIM in compensation for deferring the priority switch.

17. The method ofclaim 12, further comprising:

performing a subsequent priority switch to give the higher priority state to the second SIM in response to the first SIM having completed less than a threshold amount of a DMRS bundling repetition.

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